The present invention relates to an electronic endoscope system.
The electronic endoscope is generally provided with an endoscope unit, a main unit (a video signal processing unit), and a peripheral device including a display device.
The endoscope unit transmits light supplied from the main unit and illuminates a human body cavity. Further, the endoscope unit is provided with an image capturing device such as a CCD (Charge Coupled Device) for obtaining an image signal of the body cavity. In the endoscope unit, a signal processing circuitry is provided for processing image signals output by the CCD.
The main unit supplies illumination light as well as electrical power to the endoscope unit.
The peripheral device includes a CRT display for displaying the image obtained by the CCD, and a printer for outputting a hard copy thereof.
The main unit and the endoscope unit are connected through a connector. Electrical signals such as an image signal and transmitted from the circuitry in the endoscope unit to the main unit, and electrical power is supplied from the main unit to the endoscope circuitry through the connector. Further, the main unit and the peripheral devices are also connected through cables for transmitting electrical signals such as an image signal from the main unit to the peripheral devices.
A display condition of the displayed image, for example, a color balance thereof, contrast, and the like can be adjusted by performing predetermined operations such as signal processing operation in the main unit.
Settings of the image display is stored in a NVM (non-volatile memory) provided in the main unit, and such settings are maintained even if the main unit is powered OFF. The settings are retrieved when the main unit is powered ON next time, and an image is displayed in accordance with the retrieved settings.
In the above type of the endoscope system, when a plurality of operators use the same endoscope, a problem indicated below arises.
That is, when an operator used the endoscope system, adjusted the settings, and powered OFF the endoscope system, the adjusted setting were stored in the NVM. Thereafter, if another operator use the same endoscope system and changes the setting, then the changed settings will be stored when the endoscope is powered OFF. Thereafter, if the first operator powered ON the endoscope system again, the settings adjusted by the first operator are no more stored, and the setting made by the second operator are retrieved and made effective. In such a case, the first operator may consider the endoscope system malfunctions.
It is possible to configure the endoscope system not to store the settings adjusted by an operator. In such a case, an operator may not think the endoscope malfunctions. However, every operator must adjust the settings every time when he or she uses the endoscope system.
Further to the above, in the conventional electronic endoscope system another problem as indicated below may arise.
An operation of the endoscope system, for example, display of the image, is controlled in accordance with predetermined setting parameters.
Such setting parameters which are set during general operation, for example, a color balance of the display, a degree of enhancement of an image, can be done by switching an operation mode from a normal operation mode to a parameter setting mode.
Further, special setting parameters, for example, a gamma value, hue setting, can be set by changing the operation mode to a specific setting mode, which is different from the normal parameter setting mode. It is preferable that the special setting parameters should be changed only by authorized operators.
In the endoscope system configured as above, if the operation mode can easily be changed to the special parameters setting mode, an operator of the endoscope system may change the operation mode into the specific setting mode erroneously, and may change the specific setting parameters unintentionally.
To avoid such a situation, generally, the endoscope system is configured such that the operation mode cannot be changed to the specific setting mode until a predetermined specific operation, which cannot be performed easily, is executed. For example, in order to change the operation mode to the specific parameter setting mode, a ROM storing the special parameters is provided in a housing of the main unit is to be replaced with another ROM for maintenance work. Only when the ROM is replaced, the CPU changes the operation modes in accordance with the data stored in the ROM.
In the above type of the electronic endoscope system, in which an operator is required to perform a predetermined operation to change the operation mode from the normal setting mode to the specific parameter setting mode, although the erroneous operation is prevented, when the specific mode is to be selected, it is necessary to open the housing and the circuit board accommodated in the housing should be taken out. Such an operation is troublesome and time consuming.